Investigation the feasibility of distribution system voltage regulation with a three winding transformer

It is anticipated that with increased penetration of micro scale renewable generation sources, electric vehicles and demand response initiatives the voltage of low voltage networks need to be controlled in real time. Commonly used method of voltage control is on-load tap changing. However as this has limitations, an electronically controlled Volt-Var Control (VVC) scheme based on a three winding transformer is investigated. Two configurations based on serial injection and parallel compensation are studied for their relevant merits. A simple radial network with two loads was considered to assess the effectiveness of the proposed WC schemes against a tap changing transformer. WC approaches presented in this paper seem to be promising. However, further work is required with a more realistic transformer and a power electronically controlled voltage source converter to assess the effectiveness of this scheme.